Pupils in Reception are usually aged between four and five. Children start school either in the term or in the year in which they reach five, depending on the policy of the Local Education Authority. Reception is the final part of the Foundation Stage of education.

Most areas admit entire year groups in September, regardless of which month they were born in, meaning that some pupils will be starting primary school in the month of their fifth birthday, while others will be 11 months away from this milestone.

Other areas admit Reception pupils in the term of their fifth birthday, while some admit pupils in September if they were born between September and February, and in January if they were born between March and August.

There is no reception year in Scotland as children progress directly from Nursery to Primary 1 (equivalent to English Year One) in the August nearest their fifth birthday. Generally this means that a complete intake into P1 ranges from four and a half to five and a half years old. It is also possible for parents of children born in January and February to defer admission by one year, so as they start at five and half rather than four and a half.

Previously, children in England and Wales had started school later than children in Northern Ireland, where the starting age was generally four, dependent on the date of the child's birthday.